Head gasket questions.

[Drey6]

1981 Honda CM400E
A few questions here I want a solid answer on if any of you with the knowledge don't mind answering.
1. I've cleaned the carbon of the head and off if the tops of the pistons as good as I can and I still have some what looks like carbon and baked on old gasket still stuck to where the gasket will be. Any recommendations on that?

2. Installing the head gasket dry without sealant seems to be the correct way.
What do you think?

3. What is the name of the thin layer of sealant I put between the rocker arm/cam holder mounts?

Any answers would be great! Thanks!

 

[bjbuchanan]

Oven cleaner with ammonia in it is pretty good at removing that kind of stuff. IDK how well the "friendly" cleaner works tho I use the mean stuff. gasket remover can also be found in the sealant aisles of parts stores

Permatex no.2 is a non hardening sealer that is the sealant for the job for the cam holders

If I were you, and what I do myself, is use two layers of copper kote on the gasket. There has been some evidence that the gasket sets out there have no 'factory' sealant you could find in OEM gaskets usually. Think impregnated. The coating helps with sealing and isn't a hack job type of thing. Don't use hardening silicone if you plan on using that engine for long lol

 

[Drey6]

I've heard about copper kote being good to use. Do you just spray the gasket itself? I'm still on the fence for using anything on the head gasket just because there are so many people on other side of nothing, and a lot of fans of the copper kote.

 

[Scruffy]

Hang the gasket up on a wire, coat both side if you feel the need, and repeat. Or go to the nearest good small engine shop and get a bottle of Indian gasket cement. Pretty sure the name hasn't changed in 60 years or so, white label, red Indian in a warbonnet profile on it. It works. Copper spray works.

If the gasket doesn't feel like it was coated with something, and the package does not say to install as shipped, use some kind of cement/sealant on it. I've used the exact same gasket 5 or 6 times on one engine.

 

[Drey6]

Hang the gasket up on a wire, coat both side if you feel the need, and repeat. Or go to the nearest good small engine shop and get a bottle of Indian gasket cement. Pretty sure the name hasn't changed in 60 years or so, white label, red Indian in a warbonnet profile on it. It works. Copper spray works.

If the gasket doesn't feel like it was coated with something, and the package does not say to install as shipped, use some kind of cement/sealant on it. I've used the exact same gasket 5 or 6 times on one engine.

Thanks for the info Scruffy.

 

[Drey6]

What I did:
Cleaned the gasket head surfaces, torqued all bolts to spec and followed the honda shop manual to a "T" as best as I could.

Anddddd, still a leak ( slow, out of the front left side ) can't tell exactly where from)
The only hope I have is what I have read awhile back on taking the cover of and retorquing all the head bolts again in correct pattern to double check after the initial start and run once it has been reassembled.

Sorry to revive this thread, just curious to see what anyone thinks.

 

[mydlyfkryzis]

Also, Permatex #2 isn't the best choice....Hondabond or Threebond is the factory sealant. Yamaha has Yamabond also has a machined surface sealant that works. My understanding is that the Threebond company actually supplies Honda and Yamaha with their labeled sealants. Permatex makes Motoseal Ultra grey which is also the right stuff. Amazon has it all...do a search...

 

[Drey6]

Not so much an issue of the metal to metal surfaces as much as it is that it's leaking once again. The head wasn't warped ( one of the first things I checked before throughly cleaning the surface before reassembly). That's why I trusted to replace it this time and take the time to torque all bolts accordingly so it is done by the manuals standards and I'm not sure at this point why there is a leak. Trust me I have searched and racked my brain, read threads for weeks, to ensure this second time all is done correctly. I'm unsure why I am at the point, once again, with the leak. This is my dilemma.